I was considering making some shelter for the forage fish as well as the SMB for the deeper sections of the pond for over winter.
I have always believed that using structure in the bottom of a pond for shelter of the larger fish is not necessary. However the deep water structure will serve as fish attractors to congregate fish for anglers, but I doubt it serves as a type of shelter as is often used by land animals and humans.
Adding dense cover in shallow shoreline water for forage fish is beneficial during all seasons. Studies have proven that the most beneficial cover for forage fish is when 20%-30% the total shoreline contains the dense cover. Forage fish especially the smallest ones rarely use deep structure because this is where the predators usually frequent so small fish quickly learn from hatching that the safest place is the shallowest water where commonly dense cover occurs.
When I shovel snow from pond ice, I commonly see numerous minnows when disturbed quickly move from the shallowest water into deeper water. This taught me that minnows even in winter are usually inhabiting the shallowest water, commonly not deeper sections where the predators are frequently present.
